ERC173

1. ERC173简介

该协议定义了拥有或控制合约的标准功能。

2. ERC173的工作原理

ERC-173还要求合约同时还应该实现ERC165接口。

接口如下：

interface ERC173 /* is ERC165 */ {
    /// @dev This emits when ownership of a contract changes.    
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /// @notice Get the address of the owner   
    /// @return The address of the owner.
    
    function owner() view external returns(address);
	
    /// @notice Set the address of the new owner of the contract
    /// @dev Set _newOwner to address(0) to renounce any ownership.
    /// @param _newOwner The address of the new owner of the contract  
    
    function transferOwnership(address _newOwner) external;	
}

查询当前合约的owner，以及转让当前合约的所有权。

注：如果执行转移所有权操作的时候，应该注意_newOwner的值不能为零地址，如果将合约转移给了零地址，那么该合约将不属于任何人。

3. 与Ownable.sol的区别

Ownable.sol是基于ERC173的理念拓展完善的，丰富了关于owner的相关操作，比如对owner的检查，还有对不能将还有转让给零地址；同时也加入了一些访问控制，让transferOwnership函数更安全。